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StatusOngoing
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Status date2025-05-30
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Activity Code5D.043
The objective of this project is to develop a flexible inter-satellite link (FISL) transceiver based on Satlab’s modular transceiver platform. Building upon prior work supported by a national research grant, the project leverages the baseband hardware developed for CubeSat and MicroSat applications, where mass, size, and power constraints are critical. The transceiver design originates from Satlab’s flight-proven SRS-4 S-band module, with over 100 units currently in orbit.
This activity focuses on extending the baseband module with new firmware to enable inter-satellite communication, including message routing and support for relevant waveforms. Additionally, a hardware front-end suitable for half-duplex operation on the S-band is developed. While the primary focus remains on S-band - reflecting current market demand - the design ensures flexibility for adaptation to higher frequency bands, such as X- and K-band, through incremental development.
An EM unit is developed, built, and tested as part of this project. The resulting EM unit serves both as a demonstration platform to engage prospective customers and as a foundation for further investment aimed at achieving a flight-ready product.
A key challenge is integrating advanced features like Direct Sequence Spread Spectrum (DSSS) while keeping power consumption low to ensure energy efficiency. The product must also be highly configurable to meet diverse customer needs, yet simple to use and easy to integrate. Striking the right balance between flexibility and usability is crucial. Additionally, fitting all required features into a small form factor without sacrificing performance poses a significant design challenge, requiring careful optimisation of both hardware and system architecture.
Satlab’s Flexible Inter-Satellite Link (FISL) solution offers a modular, scalable approach to satellite communication, built on a decade of proven space heritage. Designed for CubeSat and MicroSat missions, it enables direct satellite-to-satellite communication, reducing latency, increasing coverage, and minimising reliance on ground stations. The flexible architecture supports mission-specific front-ends while maintaining a common baseband, allowing rapid adaptation to customer needs. With a focus on the S-band and a roadmap toward higher frequencies, the FISL transceiver is a future-proof solution that combines reliability, adaptability, and performance, enabling cost-effective and efficient satellite networking for modern space missions.
The product is designed to deliver strong and reliable communication performance with 2 W of output power, enabling the closure of links even over long distances. It incorporates spread spectrum support to comply with Power Spectral Density (PSD) limits, improving interference resistance and ensuring regulatory compatibility in various environments. Fast acquisition capabilities allow for quick link establishment and fast turn-around times, which is especially valuable in half-duplex communication scenarios where efficiency is critical.
The system operates in half-duplex mode using the same frequency for both receiving (RX) and transmitting (TX). This design choice eliminates the dependency on specific filters in other nodes across the network, resulting in a more flexible and simplified system architecture.
With a strong focus on minimising size, weight, and power consumption, the product is well-suited for applications where space and energy efficiency are essential. It is offered as a fully integrated, single-module solution, making it easy to adopt and implement into existing systems with minimal effort, reducing time-to-market for end products.
The Flexible Inter-Satellite Link (FISL) system features a modular architecture composed of a front-end hardware module, a baseband hardware unit, and configurable firmware. Each module adheres to the PC/104 form factor to ensure compatibility with CubeSat and MicroSat platforms.
The front-end hardware handles signal amplification, filtering, and frequency conversion (up/down mixing) between the S-band (2200–2290 MHz) and intermediate frequencies. It delivers up to 2W TX power, supports RX/TX switching, and maintains a noise figure below 2.5. Selection of critical RF components - especially the power amplifier and switching circuit - is key.
The baseband hardware supports modulation and demodulation across multiple front-end configurations. Its flexible design ensures broad applicability across mission types.
The firmware manages protocol-layer functionality and allows in-orbit configurability of key parameters, including chip rates (100–5000 kcps), DSSS spreading (1–32), error correction (convolutional and Reed-Solomon), and modulation (BPSK/QPSK). Fast signal acquisition is a priority.
The combined system has a form factor similar to the Satlab SRS-4, with a height under 40 mm, total mass below 400 g, and RX power consumption under 2W—ideal for low-SWaP space missions requiring adaptable inter-satellite communication.
The project is divided into three key phases and associated reviews: The System Requirements Review (SRR), to validate all system requirements, the Mid-Term Review (MTR), to assess design progress and prototype evaluation and the Final Review (FR) to verify the final product against requirements and prepare for delivery. Each milestone ensures the project stays on track and meets its objectives.
The project has recently commenced with the kickoff meeting, and is planned for completion in Q2 2026.
